This invention relates to a steam iron with a steam generating device for the generation of steam and with an application device for releasing additives to the steam, and a valve device therefor.
In connection with steam irons a variety of additives are in use which are applied to the objects needing to be treated with steam. During ironing, ironing auxiliaries, starch, sliding agents, softeners, fragrances, cleaning agents, products for fabric care, perfumes, impregnating agents, etc. are applied to the laundry to be ironed (cf., for example, WO 91/19037 or WO 95/06154). For this purpose, it is conventional practice to feed the additive into the water reservoir or the water supply of the steam iron, so that the additive is evaporated together with the water and, combining with the steam, is applied to the laundry (cf. U.S. Pat. Nos. 5,138,778, 5,526,595, EP 06 29 736 A1, GB 23 04 740 A). This approach has, however, the disadvantage that residues of the additives deposit in the fluid circuit and the steam generating device, in particular in the steam generating chamber, and in cases where, for example, steam irons equipped with a steam burst function are involved, may be discharged from the steam vents on the iron""s underside similar to scale deposits.
From DE 296 01 699 U1 a steam iron is known in which fragrances are not admixed until after the steam has already formed. To this effect, the fragrances are pressurized, sprayed into the steam through a nozzle and admixed thereto. This solution necessitates, however, an elaborate pressure application to the fragrances. In addition, the spray discharge orifice may become clogged with scale as a result of the passing steam.
By contrast, it is an object of the present invention to provide an improved steam iron which avoids the disadvantages of known solutions. In particular the invention aims to achieve a reliable and trouble-free introduction of the additives while providing a straightforward construction of the steam iron. It is a further object to provide a valve device therefor.
This object is accomplished by the invention in a steam iron of the type initially referred to in that the application device includes a capillary device for release of the additive to the steam. Accordingly, the application device is of the self-feeding type, possessing elements for supplying the additive to the steam without requiring external energy. There is no need to pressurize the additive. With the capillary device the application device has self-adjusting metering elements available which release precisely the desired amount of the additive to the steam. Advantageously, the application device operates without a nozzle for vaporizing the additive, thereby avoiding the buildup of scale.
In a further aspect of the present invention, the additive is released at a location downstream from the steam generating device, in particular in a steam distribution chamber, and admixed to the steam. This has the advantage of preventing residues from depositing and accumulating on the steam generating device. At least, however, the additive is released in an area in which it can mix with the steam, rather than with the liquid water. Preferably, this area is not identical with the area where the water is drip-fed into the steam generating chamber, but is at a location adjacent thereto where the steam passes by on its way to the steam exit.
Preferably, the capillary device is displaceably mounted in such fashion as to be movable into and removable from a steam flow path. In particular when the capillary device is not required to release additives to the steam, it may be removed from the steam flow path.
It will be appreciated that a variety of constructions are possible for the capillary device. Preferably, the capillary device includes a capillary wick. The capillary wick is advantageously dimensionally stable, resisting in particular pressure and buckling. For the capillary device provision may be made for a seal through which the capillary wick is slidable to enter the flow path of the steam. With the capillary device in the retracted position, the seal closes the steam flow path.
For sufficient rigidity, in a preferred embodiment of the present invention the capillary device includes a capillary fabric and a support carrying the capillary fabric. This enables a braiding or fabric or cloth to be used which is optimal for the capillary effect, irrespective of the mechanical properties. The support lends the required stiffness and strength. The supply of the additive takes place in the capillary fabric. With regard to the shape design, a wide variety of possibilities are available. Preferably, provision is made for a braided hose into which the support is inserted. Owing to the inner lying arrangement of the support, the additives are released to the passing steam effectively.
Conveniently, the capillary device is temperature-resistant to resist the effect of heat of the steam. In particular provision may be made for a braiding of glass filaments, with the diameter of the individual filaments of the braiding preferably amounting to between 5 and 50 xcexcm, approximately.
It will be appreciated that the capillary device may communicate directly with a reservoir storing the additive. Preferably, however, the connection between the additive storage reservoir and the capillary device is controlled by an interposed valve device. When no additives are to be released, the valve is operable to disconnect the capillary device from the additive storage reservoir. To release additives, the valve opens the connection between the additive storage reservoir and the capillary device. This has the advantage of preventing the additives from volatilizing through the capillary device when the steam iron is out of operation or when an operating mode without the release of additives is selected. With the valve device the application device may be turned on and off.
The valve device may be of a multi-piece construction. For example, a rubber-elastic shutoff element may be plug-connected with a central valve passage body. Preferably, however, the valve device is constructed as a single-piece component. Preferably, the valve device may be formed of a soft plastic material, in particular the valve device is a single-piece rubber part, that is, it is made of a rubber-elastic material. This affords simplicity of construction and an uncomplicated assembly.
According to an advantageous embodiment of the invention, a shutoff element for shutting off the valve passage extends in the shape of a collar or cup rim from a central valve passage body comprising at least one valve passage, said shutoff element being adapted to be turned up from a position as manufactured into an operating position. In the non-turned-up position in which the valve is manufacturable, the shutoff element extends from one side of the central valve passage body into a direction away from the valve passage body, so that the shutoff element forms a type of pedestal for the valve passage body. After the shutoff element is turned up, the central valve passage body lies with at least one section thereof, which contains the at least one valve passage, within a chamber bounded by the shutoff element as a circumferential wall in cup shape. With the shutoff element turned up, in particular a sealing surface thereof is biased toward the valve passage body. In this position the shutoff element is movable between a shutoff position in which the sealing surface of the shutoff element makes engagement with the valve passage body and a flow position in which the valve passage is in fluid communication with the additive storage reservoir. Preferably, the shutoff element is adapted to snap back and forward in bistable or monostable fashion between the closed position and the open position. The one-piece construction of the valve device notwithstanding, the turnup configuration of the shutoff element affords simplicity of manufacture substantially without cores, for example, when it is manufactured using an injection molding or casting process.
For accurate metering of the released additive, the valve device includes in a preferred embodiment of the invention a buffer reservoir which is disconnected from the additive storage reservoir with the valve device in closed condition and is connected with a discharge side. This enables a metered charge to be obtained. The buffer reservoir is filled with the shutoff element in open position. Once the shutoff element is in the closed position, only such amount of additive as is held in the buffer reservoir can be released. Preferably, the buffer reservoir is formed by a cavity defined by the valve passage body and the shutoff element.
To achieve a good sealing effect between the shutoff element and the valve passage body, a conical sealing fit is conveniently provided between these two parts. The conical sealing surfaces provide the high sealing effect in the presence of low biasing forces.
In a further aspect of the present invention, simplicity of construction of the application device may be accomplished in that the capillary device is securable directly to the valve device. To this effect the valve device may include a mount, in particular a holding fixture, into which the capillary device is insertable.
According to a preferred embodiment of the invention, the valve device has integrally formed on it a reservoir seal to effect a seal on the additive storage reservoir, in particular the shutoff element may be connectable with the additive storage reservoir in a sealing fashion.
In a particularly advantageous embodiment of the invention, the valve device is constructed as the valve head of a storage cartridge, said valve head, by pushing it into the cartridge interior, being movable into an open position. In this arrangement the valve head may be designed to protrude beyond the cartridge housing in longitudinal direction so that opening of the valve can be effected by the application of pressure against an end surface opposite the head. Preferably, the shutoff element is connected with the cartridge so that pressure exerted on the elastically biased valve passage body releases the valve passage. It will be understood, of course, that the reverse arrangement is also possible, yet the described connection of the shutoff element with the cartridge results in a particularly favorable and simple construction. Hence, as the valve head is pushed into the interior of the storage cartridge, the shutoff element is moved relative to the valve passage body, thereby releasing the valve passage disposed therein.
According to another advantageous aspect of the invention, the application device is configured as a separate, prior assembled replacement unit. Hence the application device is detachable from the balance of the steam iron""s body. If desired, the steam iron may also be used without the application device. Regardless of whether or not the capillary device is present, the construction of the application device as a separable module has the advantage that during operation of the steam iron a selection can be made between the application of various additives speedily and independently of the filling level of the additive storage reservoir. In particular the operations of draining a heretofore used additive from the additive storage reservoir and refilling it with the desired additive are avoided. Furthermore, when the reservoir is depleted it is only necessary to replace the application device as a unit without the need to manipulate with the additive directly. Preferably, the steam iron includes a suitable receptacle into which the application device is insertable.
The replacement unit advantageously comprises the storage cartridge, the capillary device and the valve head which sits on the cartridge and carries the capillary device.
For simplicity of operation the application device is preferably movable into and lockable in various positions, such that the release of additive by the capillary device is activatable and deactivatable. In particular the storage cartridge may be displaceable and lockable in position, so that the valve head opens and closes and the capillary device is moved into and out of the steam path. Advantageously, provision is made for a locking mechanism fixing the application device in the desired position.
In a further aspect of the invention, ease of operation using an operator""s fingers, in particular a thumb, is accomplished by providing for the application device to be insertable from above into a recess accessible from the outside and terminating in a gripping area. Accordingly, the cartridge itself is the control element of the application device.
To be able to apply the additive to the object to be treated also independently of the steam application, the application device may be brought into fluid communication with a spraying device for spraying the objects to be treated. Surfaces requiring particularly intensive treatment, for example, may thus receive an increased amount of the additive.
With regard to the valve device, the invention object is accomplished with the features of claim 24. The valve device is advantageously formed of a one-piece, rubber-type body whose elasticity and shape are utilized to provide the resilient opening and closing motion. In addition, a rim of the rubber-type valve device is secured to the fluid reservoir in such manner that a minor deformation produces a tight connection. Neither a spring nor an O-ring seal are necessary additionally.